全文获取类型
收费全文 | 318899篇 |
免费 | 20442篇 |
国内免费 | 6557篇 |
专业分类
耳鼻咽喉 | 2215篇 |
儿科学 | 5200篇 |
妇产科学 | 4823篇 |
基础医学 | 36166篇 |
口腔科学 | 8125篇 |
临床医学 | 23141篇 |
内科学 | 45834篇 |
皮肤病学 | 4271篇 |
神经病学 | 20739篇 |
特种医学 | 9622篇 |
外国民族医学 | 8篇 |
外科学 | 34384篇 |
综合类 | 40254篇 |
现状与发展 | 22篇 |
一般理论 | 17篇 |
预防医学 | 26916篇 |
眼科学 | 4306篇 |
药学 | 36642篇 |
199篇 | |
中国医学 | 25916篇 |
肿瘤学 | 17098篇 |
出版年
2023年 | 4107篇 |
2022年 | 5893篇 |
2021年 | 12417篇 |
2020年 | 10104篇 |
2019年 | 14757篇 |
2018年 | 14331篇 |
2017年 | 12782篇 |
2016年 | 10036篇 |
2015年 | 9282篇 |
2014年 | 13577篇 |
2013年 | 17041篇 |
2012年 | 14284篇 |
2011年 | 17185篇 |
2010年 | 12292篇 |
2009年 | 11342篇 |
2008年 | 12626篇 |
2007年 | 13590篇 |
2006年 | 12693篇 |
2005年 | 11400篇 |
2004年 | 9605篇 |
2003年 | 8651篇 |
2002年 | 6735篇 |
2001年 | 6112篇 |
2000年 | 5075篇 |
1999年 | 4416篇 |
1998年 | 3398篇 |
1997年 | 3472篇 |
1996年 | 2885篇 |
1995年 | 2840篇 |
1994年 | 2724篇 |
1993年 | 2253篇 |
1992年 | 2092篇 |
1991年 | 1942篇 |
1990年 | 1642篇 |
1989年 | 1418篇 |
1988年 | 1362篇 |
1987年 | 1239篇 |
1985年 | 4840篇 |
1984年 | 5627篇 |
1983年 | 4831篇 |
1982年 | 4945篇 |
1981年 | 4381篇 |
1980年 | 3824篇 |
1979年 | 3687篇 |
1978年 | 2999篇 |
1977年 | 2220篇 |
1976年 | 2836篇 |
1975年 | 2200篇 |
1974年 | 1937篇 |
1973年 | 1856篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
《Vaccine》2022,40(11):1594-1605
In addition to providing pathogen-specific immunity, vaccines can also confer nonspecific effects (NSEs) on mortality and morbidity unrelated to the targeted disease. Immunisation with live vaccines, such as the BCG vaccine, has generally been associated with significantly reduced all-cause infant mortality. In contrast, some inactivated vaccines, such as the diphtheria, tetanus, whole-cell pertussis (DTPw) vaccine, have been controversially associated with increased all-cause mortality especially in female infants in high-mortality settings. The NSEs associated with BCG have been attributed, in part, to the induction of trained immunity, an epigenetic and metabolic reprograming of innate immune cells, increasing their responsiveness to subsequent microbial encounters. Whether non-live vaccines such as DTPw induce trained immunity is currently poorly understood. Here, we report that immunisation of mice with DTPw induced a unique program of trained immunity in comparison to BCG immunised mice. Altered monocyte and DC cytokine responses were evident in DTPw immunised mice even months after vaccination. Furthermore, splenic cDCs from DTPw immunised mice had altered chromatin accessibility at loci involved in immunity and metabolism, suggesting that these changes were epigenetically mediated. Interestingly, changing the order in which the BCG and DTPw vaccines were co-administered to mice altered subsequent trained immune responses. Given these differences in trained immunity, we also assessed whether administration of these vaccines altered susceptibility to sepsis in two different mouse models. Immunisation with either BCG or a DTPw-containing vaccine prior to the induction of sepsis did not significantly alter survival. Further studies are now needed to more fully investigate the potential consequences of DTPw induced trained immunity in different contexts and to assess whether other non-live vaccines also induce similar changes. 相似文献
82.
Jeffrey Buenaflor Parker Sommerville Hang Qian Christine Luscombe 《Macromolecular chemistry and physics.》2020,221(2)
A comparative study involving bimetallic nickel catalysts designed from disubstituted N,N,N′,N′‐tetra(diphenylphosphanylmethyl)benzene diamine bridging ligands is reported. Catalyst behavior is explored in the Kumada catalyst‐transfer polymerization (KCTP) using poly(3‐hexylthiophene) (P3HT) as the model system. The success of a controlled polymerization is monitored by analyzing monomer conversion, degree of polymerization, end‐group identity, and molecular weight distribution. The characterization of P3HT obtained from KCTP initiated with the bimetallic catalysts shows chain‐growth behavior; however, the presence of Br/Br end‐groups and broader molecular weight distribution reveals a reduced controlled polymerization compared to the commonly employed Ni(dppp)Cl2. The observed increase in intermolecular chain transfer and termination processes in KCTP initiation with the bimetallic catalysts can be attributed to a weaker Ni(0)‐π‐aryl complex interaction, which is caused by increased steric crowding of the coordination sphere. 相似文献
83.
《European journal of medical genetics》2020,63(9):103981
Congenital diarrhea and enteropathies (CODEs) are a group of monogenic disorders that often present with severe diarrhea in the first weeks of life. Enteric anendocrinosis (EA), an extremely rare cause of CODE, is characterized by a marked reduction of intestinal enteroendocrine cells (EC). EA is associated with recessively inherited variants in Neurogenin-3 (NEUROG3) gene. Here we investigate a case of a male infant who presented with mysterious severe malabsorptive diarrhea since birth. Thorough clinical assessments and laboratory tests were successful to exclude the majority of differential diagnosis categories. However, the patient's diagnosis was not established until the genetic test using whole-exome sequencing (WES) was performed. We identified a novel homozygous missense disease-causing variant (DCV) in NEUROG3 (c.413C>G, p.Thr138Arg). Moreover, molecular dynamic simulation analysis showed that (p.Thr138Arg) led to a global change of the NEUROG3 orientation affecting its DNA binding capacity. To the best of our knowledge, this is the first time to apply WES to reach a differential diagnosis of patients with CODEs. Our study not only expands our knowledge about NEUROG3 variants and their clinical consequences but also proves that WES is a very effective tool for the diagnosis of CODEs. This might be of value in early diagnosis of diseases and prenatal CODEs detection. 相似文献
84.
For children with Developmental Coordination Disorder (DCD), the real-time coupling between frontal executive function and online motor control has not been explored despite reported deficits in each domain. The aim of the present study was to investigate how children with DCD enlist online control under task constraints that compel the need for inhibitory control. A total of 129 school children were sampled from mainstream primary schools. Forty-two children who met research criteria for DCD were compared with 87 typically developing controls on a modified double-jump reaching task. Children within each skill group were divided into three age bands: younger (6–7 years), mid-aged (8–9), and older (10–12). Online control was compared between groups as a function of trial type (non-jump, jump, anti-jump). Overall, results showed that while movement times were similar between skill groups under simple task constraints (non-jump), on perturbation (or jump) trials the DCD group were significantly slower than controls and corrected trajectories later. Critically, the DCD group was further disadvantaged by anti-jump trials where inhibitory control was required; however, this effect reduced with age. While coupling online control and executive systems is not well developed in younger and mid-aged children, there is evidence of age-appropriate coupling in older children. Longitudinal data are needed to clarify this intriguing finding. The theoretical and applied implications of these results are discussed. 相似文献
85.
Interstitial cystitis/bladder pain syndrome (IC/BPS) and vulvodynia are chronic pain syndromes that appear to be intertwined from the perspectives of embryology, pathology and epidemiology. These associations may account for similar responses to various therapies. 相似文献
86.
This retrospective study aimed to evaluate radiation-induced pneumonitis (RIP) and a related condition that we define in this report—prolonged minimal RIP (pmRIP)—after stereotactic body radiotherapy (SBRT) for Stage I primary lung cancer in patients with chronic obstructive pulmonary disease (COPD). We assessed 136 Stage I lung cancer patients with COPD who underwent SBRT. Airflow limitation on spirometry was classified into four Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades, with minor modifications: GOLD 1 (mild), GOLD 2 (moderate), GOLD 3 (severe) and GOLD 4 (very severe). On this basis, we defined two subgroups: COPD-free (COPD −) and COPD-positive (COPD +). There was no significant difference in overall survival or cause-specific–survival between these groups. Of the 136 patients, 44 (32%) had pmRIP. Multivariate analysis showed that COPD and the Brinkman index were statistically significant risk factors for the development of pmRIP. COPD and the Brinkman index were predictive factors for pmRIP, although our findings also indicate that SBRT can be tolerated in early lung cancer patients with COPD. 相似文献
87.
88.
89.
《Neuro-Chirurgie》2022,68(3):262-266
BackgroundThe prognosis for patients with recurrent glioblastoma (GBM) is dismal, and the question of repeat surgery at time of recurrence is common. Re-operation in the management of these patients remains controversial, as there is no randomized evidence of benefit. An all-inclusive pragmatic care trial is needed to evaluate the role of repeat resection.Methods3rGBM is a multicenter, pragmatic, prospective, parallel-group randomized care trial, with 1:1 allocation to repeat resection or standard care with no repeat resection. To test the hypothesis that repeat resection can improve overall survival by at least 3 months (from 6 to 9 months), 250 adult patients with prior resection of pathology-proven glioblastoma for whom the attending surgeon believes repeat resection may improve quality survival will be enrolled. A surrogate measure of quality of life, the number of days outside of hospital/nursing/palliative care facility, will also be compared. Centers are invited to participate without financial compensation and without contracts. Clinicians may apply to local authorities to approve an investigator-led in-house trial, using a common protocol, web-based randomization platform, and simple standardized case report forms.DiscussionThe 3rGBM trial is a modern transparent care research framework with no additional risks, tests, or visits other than what patients would encounter in normal care. The burden of proof remains on repeat surgical management of recurrent GBM, because this management has yet to be shown beneficial. The trial is designed to help patients and surgeons manage the uncertainty regarding optimal care.Clinical Trial Registrationhttp://www.clinicaltrials.gov. Unique identifier: NCT04838782. 相似文献
90.